Brake shoe clearance gage

ABSTRACT

A brake lining gage is disclosed for supporting a brake shoe in a test plane to measure the clearance or interference between various points on the lining and a simulated standard brake drum. The gage has a base on which parts of a brake mechanism are adjustably simulated. A center post mounted on the base simulates the center of a standard brake drum. Various size anchor pins are movably mountable individually on the base for radial adjustment. An outside diameter locater post is similarly movably mounted to the base for radial adjustment. A series of arcuately spaced radial slots are provided in the base in adjacent quadrants on each side of the outside diameter locater post for slidably receiving radially adjustable distance indicating meters having radially operable sensing members. The anchor pin, the outside diameter locater post, and the meters are accurately adjusted into position with reference to the center post by means of setting bars which seat at one end against the center post and are radially aligned toward the piece being adjusted. A set of several such setting bars is provided corresponding to various standard brake mechanism dimensions.

United States Patent [451 Aug. 22, 1972 MacKeigan [54] BRAKE SHOECLEARANCE GAGE [72] Inventor: Thomas H. MacKeigan, Windsor,

Ontario, Canada [73] Assignee: Abex Corporation, New York, NY.

[22] Filed: Aug. 5, 1970 [21] Appl. No.: 61,303

[52] US. Cl ..33/18l AT, 33/171, 33/172 R [51] Int. Cl. ..G01b 5/14 [58]Field of Search.33/180 AT, 181 AT, 172 R, 171

[56] References Cited UNITED STATES PATENTS 2,087,497 7/1937 Blackman..33/180 AT 3,241,244 3/1966 Jones ..33/l80 AT 3,073,035 1/1963 Thomason..33/l80 AT 2,268,171 12/1941 Sikora ......33/180 AT 1,965,843 7/1934Kuhle ..33/l80 AT Primary ExaminerWilliam D. Martin, Jr. Attorney-FrankH. Foster and James R. Cox

[ 5 7] ABSTRACT A brake lining gage is disclosed for supporting a brakeshoe in a test plane to measure the clearance or interference betweenvarious points on the lining and a simulated standard brake drum. Thegage has a base on which parts of a brake mechanism are adjustablysimulated. A center post mounted on the base simulates the center of astandard brake drum. Various size anchor. pins are movably mountableindividually on the base for radial adjustment. An outside diameterlocater post is similarly movably mounted to the base for radialadjustment. A series of arcuately spaced radial slots are provided inthe base in adjacent quadrants on each side of the outside diameterlocater post for slidably receiving radially adjustable distanceindicating meters having radially operable sensing members. The anchorpin, the outside diameter locater post, and the meters are accuratelyadjusted into position with reference to the center post by means ofsetting bars which seat at one end against the center post and areradially aligned toward the piece being adjusted. A set of several suchsetting bars is provided corresponding to various standard brakemechanism dimensions.

8 Claims, 6 Drawing Figures Pmmimus m I u slsesJs-o -snm1nr3 FIG I unv4,] 34 5 INVENTOR. THOMAS H. MACKEIGAN FWWFJM ATTORNEY I v PATENTED Am;22 I972 3.685160 SHEET 2 0F 3 N TE 4 if m H F m. w W 3 Y B ATTO RNEYPATENTEflAuszz 1972 SHEET 3 BF 3 INVENTOR. OMAS H. MACKEIGAN ATTORNEYBRAKE SHOE CLEARANCE GAGE BACKGROUND OF THE INVENTION This relates tomeasuring fixtures for measuring critical dimensions of an object andmore particularly relates to a gage for measuring the prospectiveclearance or interference between a lined brake shoe and its mating drumat various arcuately spaced points along the brake lining.

A conventional drum-type brake mechanism has a rotatable drum with acylindrical interior and a pair of non-rotating shoes which arepivotally mounted within the drum and have linings mounted on theirexteriors. The exterior surface of the lining on each shoe is arcuatelyformed for frictional engagement with the drum. The arcuate surface ofeach shoe lining is formed with a radius slightly less than the drumradius with the result that the normal shoe lining initially contactsthe drum centrally at a single line. The remaining shoe lining surfaceat initial contact willbe spaced from the drum. This clearance will,with an unwom shoe lining, be progressively greater at further distancesfrom the central line of initial contact. A distorted shoe or improperlyshaped lining may make its initial contact at a position other than theintended initial contact position. This interference can resultinimproper operation of the brake mechanism.

It follows that it is not only desirable to measure such clearance orinterference but also it is desirable to make these measurements on amachine or work bench before the shoe is installed in the brakemechanism. This is particularly advantageous where brake shoe liningsare being ground to desired dimensions to operate with a particularbrake drum.

Diverse devices have been proposed and used for measuring clearance andinterference either of the assembled brake mechanism or of anunassembled shoe. For example, devices are shown in the US. Pats. toKuhle No. l,965,843; Thomason No. 3,073,035; Comstock No. 2,593,986; andWasley No. 3,139,685.

There is a need for a device which can provide measurement with improvedaccuracy. One basis for the impaired accuracy of these prior devices isthat, generally, they do not establish a fixed point for simulating theinitial contact point of the drum with the shoe lining. A gage is neededwhich establishes such a fixed initial contact point and which thenpermits measurements at angular intervals on opposite sides of theinitial contact point.

There is also a need for a device which establishes a fixed drum centerpoint. This need arises because in an actual brake mechanism, the centerpoint is the manufacturing reference point. Yet, many prior art devicesutilize the anchor pin or the drum as the reference point ofmeasurements and consequently may introduce error into themeasurementsdue to a deviation in the anchor pin position or drum position relativeto the center point.

Some of the previous devices, such as the Thomason device, require theuse of an actual brake drum. Thus to permit measurement of various sizedshoes several different sized drums are needed. There is therefore aneed for a device which does not require the use of ac.- tual drums.Furthermore, there is a need for a device which can simulate the anchorpin and the brake drum and which can also permit the anchor pin positionand the brake drum position to be independently adjusted to an unlimitednumber of positions within a useful range.

SUMMARY OF THE INVENTION The invention is a brake lining gage forsupporting a brake shoe in a test plane for measurement of clearancesand interferences between a simulated standard brake drum and the liningof the shoe. The gage has a base with several structures mounted to it.-An anchor pin is mounted to the base and extends through andperpendicular to the test plane for seating against the anchor eye ofthe brake shoe at a position simulating the anchor pin of a brakemechanism. An outside diameter locater means is also mounted to thebase, the locater means having a locating surface extending through thetest plane for seating against the lining at a position simulating andcorresponding to a standard initial contact point for the shoe liningand the drum. At least one distance indicating meter'is mounted to thebase radially outwardly from the center of the simulated drum and havinga radially operable sensing member seatable against the shoe lining forindicating the radial distance from a simulated drum to the shoe liner.The meter is calibrated to the standard drum radius, a brake shoe isthen positioned on the gage with its anchor eye seated against theanchor pin and its lining seated against the locater means, and themeter sensing member will then indicate the clearance or interferencebetween the drum and the shoe lining.

The gage also includes a center post mounted to the base extendingthrough and perpendicular to the test plane and spaced from the anchorpin at a position simulating the center of the standard brake drum. Aset of drum radius setting bars and a set of anchor pin setting bars areprovided. Each bar has an effective length corresponding to specificbrake mechanism dimensions and is used to accurately position the anchorpin, the locater means, and the meter the proper distance from thecenter post.

An object of the invention is to provide for the measurement of thelining, ground on a brake shoe, to permit accurate control of the liningsurface so that it will make the desired contact with the drum and havethe proper clearance on opposite sides of the initial contact point. I

A further object is to provide a gage which establishes a fixed pointfor simulating the initial contact point of the shoe lining with thedrum and also a fixed drum center point from which measurements aremade.

Another object of the invention is to provide an inexpensive, easilyassembled and easily used gage.

Another object is to provide a gage which can alternatively measure theclearance or interference of a brake shoe without the necessity ofmounting the shoe in a brake drum.

Yet another object of the invention is to provide a gage which canmeasure the clearance or interference between a brake shoe and anon-standard brake drum.

Another object of the invention is to provide a gage which measures theclearance or interference for the shoe in its engaged position againstthe drum rather than in its disengaged position.

surements at various selected positions across the width of the lining.

Further objects and features of the invention will be apparent from thefollowing specification and claims when considered in connection withthe accompanying drawings illustrating several embodiments of myinvention.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a view in perspective of a brakeshoe clearance gage made according to the invention showing a brake shoemounted in position on the gage;

FIG. 2 is a plan view of the base plate of the embodiment illustrated inFIG. 1, illustrating the positioning of the anchor pin;

FIG. 3 is a plan view of the base plate illustrated in FIG. 1 showingthe positioning of the brake drum locater means;

FIG. 4 is a plan view of the base plate of FIG. 1 illustrating thecalibration of the distance indicating meter;

FIG. 5 is a plan view of thebase plate of FIG. 1 showing a brake shoe inproper position on the gage for measurement; and

FIG. 6 is an exploded front elevation of the gage illustrated in FIG. 5showing the apparatus mounted thereon exploded.

In describing the preferred embodiment of the invention illustrated inthe drawings, specific terminology will be resorted to for the sake ofclarity. However, it isnot intended to be limited to the specific termsso selected, and it is to be understood that each specific term includesall technical equivalents which operate in a similar manner toaccomplish a similar purpose.

DETAILED DESCRIPTION An assembled brake shoe clearance gage madeaccording to the invention is illustrated in FIG. 1. Describedgenerally, the gage has a flat base plate 10 beneath which a supportingleg structure 12 is connected so that the base plate 10 may be set on awork table and held in an oblique or vertical position transverse to thework table. Mounted to a lower portion of the base plate 10 is an anchorpin 14 which is mounted on a slidably adjustable micrometer carriage 16.Several such anchor pins of various sizes are available. Mounted to theleft central portion of the base plate 10 is an outside diameterlocating post 18 similarly mounted on its own slidable micrometercarriage 20. A distance indicating meter 22, for measuring brake liningclearance and interference is also mounted on the base plate 10. Twosuch meters are normally preferred. A center post 24 is mounted in abore in the central right portion of the base plate 10. FIG. 1 alsoshows a brake shoe 26 mounted on the gage for measurement.

FIGS. 2 through 5 show the structures illustrated in FIG. 1 in moredetail. The base plate 10, as seen best in FIGS. 2 and 3, is arectangular flat plate having several bores and slots cutperpendicularly through the plate. As best seen in FIG. 3, a radiallyaligned series of anchor bores 30A30E are provided in the base 10 forpositioning the anchor pin 14 in a selected position. A series ofoutside diameter locater bores 32A-32E, best viewed in FIG. 2, arealigned along a radius which is perpendicular to the radius of alignmentof the anchor bores 30A30E. These locater bores 32A-32E are used toselectively position the outside diameter locating post 18 in a mannerto be described. The spacing between the bores 30A30E and between thebores 32A-32E is dependent upon the range of travel of the micrometersof the carriages 16 and 20. They must be close enough to permit acontinuum of positions. The base 10 also has a series of arcuatelyspaced, radial slots such as slots 35 and 36 at selected angularintervals on opposite sides of the outside diameter locater bores32A-32E. These radial slots are used for slidably mounting the meter 22in selected slots to permit radial adjustment. Preferably, six slots arespaced at 10 intervals on each side of the locater bores 32A-32E. Acutout is provided in the upper right corner of the base 10. The cut-outhas a linear reference surface 38. The reference surface 38 is alignedon that diameter of the simulated brake drum which extends through thecenter post 24 and the radially aligned anchor bores 30A30E. A pair ofsupport leg bores 40 and 42 are provided in the base 10 for snug receiptof the legs of the supporting leg structure 12.

The center post 24 is seen best in FIG. 6 and comprises a lower shankportion 44 and an upper cylindrical portion 46 of smaller diameter. Aslidable collar 48 is frictionally engaged onthe upper portion 46. Thecenter post 24 is mounted to the base plate 10 with its threaded screwportion 27 inserted in a hole and is clamped to the base plate 10 by anut 25 engaged on its screw portion 27. The center of the center post isat a position simulating the center of a standard brake drum.

The anchor pin 14 is a cylindrical rod mounted to a micrometer carriagel6. Anchor pins of various sizes are available, typically 0.622 0.812inches in diameter, to correspond to the anchor pin sizes of variousstandard brake mechanisms. The micrometer carriage 16 comprises an upperslide 50 mounted on a base member 52. The slide 50 has a dovetail tongue54 which is slidably received in a mating groove in the base member 52and may be locked in its adjusted position by a tension clamp 51. Amicrometer 56 is clamped in the base member 52 by a screw 57 in order topermit accurate adjustment of the anchor pin 14 to a desired radialdistance from the center of the center post 24. The base member 52 ofthe micrometer carriage 16 is bolted by a bolt 58 in a selected one ofthe radial series of anchor bores 30A30E.

The outside diameter locater means 18 is preferably a cylindrical shaftmounted to a similar micrometer carriage 20. However, the shape or sizeof the locater means is unimportant. It need only have a surface whichcan seat against the brake lining. The micrometer carriage 20, like themicrometer carriage 16, comprises a slide 60 and a base member 62. Thedove-tail tongue 64 of the slide 60 is received in a mating groove inthe base member 62 and is slidably adjusted by means of a micrometerscrew 66. The slide 60 is fixed in its adjusted position by a tensionclamp 55. A guide pin 68 is provided in the bottom of the base member 62for insertion in one of the radial series of locater bores 32A-32E. Abolt 69 extends through the base plate into a threaded bore in thebottom of the base member 62 for attaching the micrometer carriage 20 tothe base 10. The anchor pin micrometer carriage 16 is also provided witha similar guide pin not shown. The outside diameter locating means 18has a surface 70 extending through the test plane for seating againstthe brake shoe lining at a position simulating and corresponding to astandard initial contact point of the shoe on the simulated brake drum.

The distance indicating meter 22 is mounted on its support 72 radiallyoutwardly from the center of the simulated drum. It has a radiallyoperable sensing member 74 seatable against the shoe-lining andindicates the radial distance from a calibrated drum radius of thesimulated standard brake drum to the shoe liner. The support 72 has abase member 76 which is attached to the base by a screw 78 extendingthrough one of the radial slots. A vertically aligned channel guide 80extends upwardly from the base plate 76 and receives a bracket 82 towhich the meter 22 is attached. The bracket 82 is slidable along thechannel 80 and may be fixed at a selected height by tightening the screw84. This also allows clearance checks across the width of the shoe. Inactual practice, it is advantageous to have two such meters mounted indifferent ones of the radial slots. Preferably, the two meters aremounted at equal angles on opposite sides of the locater post 18.

A second such meter, 22A, is shown in phantom in FIG. 5. This wouldpermit simultaneous measurement of clearance or interference on bothsides of the center contact point at the locater post 18.

The assembly and adjustment of the gage are sequentially illustrated inFIGS. 2, 3, 4, and 5. The base 10 with its attached stand 12 isinitially positioned on a work surface with the base 10 in the obliqueposition illustrated in FIG. 1. The center post 24 is then bolted intoits position on the base 10. The operator must now determine thestandard brake mechanism dimensions for the brake shoe to be tested. Forthis purpose, he is provided with tables in which these standarddimensions are tabulated for each shoe which might be tested. Themicrometer carriage 16, which carries the desired anchor pin 14, is thenmounted to particular anchor bores. The particular anchor bores areselected so that, initially, the anchor pin 14 is spaced from the centerof the center post 24 a distance which is nearest the standard distanceindicated in the table, between the anchor pin and the center of thecorresponding actual brake mechanism.

The operator is provided with several anchor setting bars such as theanchor setting bar 90 illustrated in FIG. 2. Each anchor bar has aV-slot at one end and a cylindrically shaped measuring surface at itsopposite end for properly spacing the anchor pin 14 from the center post24. The operator selects the proper anchor setting bar and, radiallyaligning it on the gage, seats the V-slot end 91 against the center post24 and the opposite end 92 near the anchor pin 14. The anchor bar 90which is selected will have an effective length for spacing the anchorpin a standard distance from the center of the center post 24. Themicrometer screw 5.6

is then rotated until the anchor pin 114 seats against the end 92 of theanchor setting bar 90. In case of overtravel, the slide must be returnedby hand and reset. The slide is fixed in this position by tightening thetension clamp 51. The anchor setting bar 90 is then removed from theassembly. If no bar is provided for a particular spacing, a bar of thenext largest length may be used and the micrometer scale of themicrometer screw 56 can be used to obtain the proper spacing.

FIG. 3 illustrates the positioning of the outside diameter locatingmeans 18. Although the anchor pin 14 and its micrometer carriage 16 areshown removed from FIG. 3 in order to reveal the anchor bores 30, inactual practice these members would remain fixed in their position onthe base 10 while the outside diameter locater means 18 is beingadjusted. The micrometer carriage 20, which carries the outside diameterlocater means 18, is attached to the base 10 at the particular outsidediameter locater bores which position the locater means 18 at a radialdistance from the center of the center post 24'which is initiallyclosestto the standard radius for the corresponding standard brake drumas shown in the table. The operator is provided with a set of severaldrum radius setting bars, each corresponding to a standard drum radiusfor various brake mechanisms. The operator selects the particular drumradius setting bar 100 for use with the brake shoe to be measured, andseats the V-slot end 102 of the setting bar 100 against the center post24 resting below the collar 48. The drum radius setting bar is radiallyaligned and has an opposite end cylindrical surface 104 which is spaceda standard drum radius from the center of the center post 24.Thissurface is used for calibrating the outside diameter locater means18. The micrometer screw 66 is now turned until the locater means 18seats against the end 104 of the drum radius setting bar 100. The slideis now clamped in this position by means of its tension clamp 55. Thedrum radius setting bar 100 is then removed so that the anchor pin 14and the outside diameter locater means 18 are fixed in position asillustrated in FIG. 4.

The meter 22 is calibrated to the standard drum radius also by use ofthe drum radius setting bar 100. The brake shoe 26, which is to betested, should temporarily be positioned on the gage as illustrated inFIG. 5. The base member 72 for the meter 22 is positioned in a selectedone of the radial slots at the angular position at which measurement ofclearance or interference is desired such as the end position of thelining on a shoe. The vertical height of the sensing member 74 of themeter 22 is now adjusted to any desired point across the width of thelining but normally at approximately the center point of the brakelining 110 by sliding the bracket 82 along the channel guide 80. It isfixed at the proper height by tightening the screw 84. The brake shoe 26is then removed and the drum radius setting bar is radially aligned onthe gage as illustrated in FIG. 4, seating as before at one end againstthe center post 24 on collar 48 and at its opposite end against thesensing member 74. The collar 48 is slid to the proper height so thatthe radius setting bar 100 can rest on the collar at the same height asthe sensing member 74. The base member 76 is then slid along the slotuntil the indicator of the meter 22 is depressed an amount sufficient toexceed the clearance to be measured which might be roughly 0.030 inches.The base member 76 is then tightened against the base 10 by a bolt 78.The indicator dial is then adjusted to read 0, which corresponds to theinterior surface of a simulated standard brake drum. The same is donewith the second meter 22A shown in phantom in FIG. 5.

The brake shoe 26 is reinserted on the gage with the anchor eye restingagainst the anchor pin 14 and the exterior surface of the brake lining110 resting against the locater means 18. It can be seen that, becauseof the angular orientation of the base 10 and the positioning andorientation of the micrometer carriages l6 and 20, the gravitationalforces exerted by the brake shoe 26 on these micrometer carriages willmaintain the slide members 50 and 60 of the micrometer carriages l6 andfirmly seated against their micrometer screws 56 and 66. Also a uniformforce holds the shoe against the locater post 18. With the brake shoe inits proper position, the reading of the meter will now indicate theclearance or interference between the brake lining surface and thestandard brake dnim diameter.

If the operator is confronted with a brake shoe with an anchor eye thathas been bent open in use, he can measure the effect of this loosenessor clearance or interference by merely moving the enlarged eye from sideto side along the anchor pin 14 and observing the measured changes atthe meters 22 and 22A.

If he wishes to measure the effect that a dimensional change of theposition of one part has on the clearance or interference, he simplymoves the corresponding part and measures the difference.

It should be noted that it would be possible, though not as flexible oruniversal, to provide an anchor pin and meter and locating means whichare inserted directly in series of bores in the base 10. This would, ofcourse, permit no adjustment of the gage. Furthermore, many other typesof carriages might instead be used for the slidable adjustment of theanchor pin, the locating means, and the meter.

It should furthermore be noted that the point of initial contact betweenthe brake lining and the brake drum in a brake mechanism ordinarily isintended to occur along a radius which is perpendicular to a radiusextending through the anchor pin. Therefore, I have correspondinglypositioned the locater means 18 along this radius. How-ever, anequivalent and obvious modification would be easily made by making minormodifications in the base 10 so that the micrometer carriage 20 for thelocater means 18 could be located along any radius at which initialcontact occurs for a particular brake mechanism.

It is to be understood that while the detailed drawings and specificexamples given describe preferred embodiments of my invention, they arefor the purposes of illustration only, that the apparatus of theinvention is not limited to precise details and conditions disclosed,and that various changes may be made therein without departing from thespirit of the invention which is defined by the following claims.

I claim:

1. A brake lining gage for supporting a brake shoe in a test plane formeasurement of clearances and interferences between a simulated standardbrake drum and the lining of the shoe, the gage comprising:

a. a base;

b. an anchor pin mounted to the base and extending through andperpendicular to the test plane for seating against the anchor eye ofthe brake shoe at a position simulating the anchor pin of a brakemechanism; I

c. an outside diameter locater means movably mounted to the base forradial adjustment the .locator means having a locating surface extendingthrough the test plane, for seating against the lining at a positionsimulating and corresponding to a standard initial contact point for theshoe lining and the drum;

(1. a distance indicating meter mounted to the base radially outwardlyfrom the center of the simulated drum and having a radially operablesensing member seatable against the shoe lining for indicating theradial distance from a simulated drum to the shoe liner;

e. a center post mounted to the base, extending through andperpendicular to the test plane and spaced from the anchor pin at aposition simulating the center of the standard brake drum; and

f. a drum radius setting bar for seating at one end against the centerpost and in radial alignment, and seating at its opposite end againstthe outside diameter locator means, the drum radius setting bar havingan opposite end surface spaced a standard drum radius from the center ofthe center post, for calibrating the outside diameter locator means tothe standard drum radius;

wherein the meter may be calibrated to the standard drum radius, a brakeshoe positioned on the gage with its anchor eye seated against theanchor pin and its lining seated against the locator means, and themeter sensing member can then indicate the clearance or interferencebetween the drum and the shoe lining.

2. A brake lining gage for supporting a brake shoe in a test plane formeasurement of clearances and interferences between a simulated standardbrake drum and the lining of the shoe, the gage comprising:

a. a base;

b. an anchor pin movably mounted to the base for radial adjustment andextending through and perpendicular to the test plane for seatingagainstthe anchor eye of the brake shoe at a position simulating theanchor pin of a brake mechanism;

c. an outside diameter locator means mounted to the base, the locatormeans having a locating surface extending through the test plane, forseating against the lining at a position simulating and corresponding toa standard initial contact point for the shoe lining and the drum;

d. a distance indicating meter mounted to the base radially outwardlyfrom the center of the simulated drum and having a radially operablesensing member seatable against the shoe lining for indicatingthe radialdistance from a simulated drum to the shoe liner;

e. a center post mounted to the base, extending through andperpendicular to the test plane and spaced from the anchor pin at aposition simulating the center of the standard brake drum; and

f. an anchor setting bar for radial alignment and for seating at one endagainst the center post and for seating at its opposite end against theanchor pin, the anchor bar having an effective length for spacing theanchor pin a standard distance from the center of the center postwherein the meter may be calibrated to the standard drum radius, a brakeshoe positioned on the'gage with its anchor eye seated against theanchor pin and its lining seated against the locator means, and themeter sensing member can then indicate the clearance or interferencebetween the drum and the shoe lining.

A brake lining gage for supporting a brake shoe in a test plane formeasurement of clearances and interfere nces between a simulatedstandard brake drum and the lining of the shoe, the gage comprising:

a base;

an anchor pin movably mounted to the base for radial adjustment andextending through and perpendicular to the test-plane for seatingagainst the anchor eyeof the brake shoe at a position simulating theanchor pin of a brake mechanism;

. an anchor setting bar for seating at one end against the center postand for seating at its opposite end a distance indicating meter movablymounted to the base for radial adjustment radially outwardly from thecenter of the simulated drum and having a radially operable sensingmember seatable against the shoe lining for indicating the radialdistance from a simulated drum to the shoe liner;

. a drum radius setting bar for seating at one end against the centerpost in radial alignment the drum radius setting bar having an oppositeend surface spaced a standard drum radius from the center of the centerpost, for seating against the sensing member of the meter forcalibrating the meter to the standard drum radius and the drum radiussetting bar is also provided for seating at one end against the centerpost in radial alignment, and seating at its opposite end against theoutside diameter locator means for calibrating the outside diameterlocator means to the standard drum radius; and

a center post mounted to the base, extending through and perpendicularto the test plane and spaced from the anchor pin at a positionsimulating the center of the standard brake drum; herein the meter maybe calibrated to the standard drum radius, a brake shoe positioned onthe gage with its anchor eye seated against the anchor pin and itslining seated against the locator means, and the meter sensing membercan then indicate the clearance or interference between the drum and theshoe lining.

4. A brake lining gage for supporting a brake shoe in a test plane formeasurement of clearances and interferences betweena simulated standardbrake drum and the lining of the shoe, the gage comprising:

a. a base having a radially aligned series of anchor bores for selectively positioning an anchor pin and series of outside diameter locatorbores aligned along a radius perpendicular to the radius of alignmentthe anchor bores for selectively positioning a locator means an anchorpin mounted to the base and extending through and perpendicular to thetest plane for seating against the anchor eye of the brake shoe at aposition simulating the anchor pin of a brake mechanism; an outsidediameter locator means mounted to the base, the locator means having alocating surface extending through the test plane, for seating againstthe lining at a position simulating and corresponding to a standardinitial contact point for the shoe lining and the drum; and d. adistance indicating meter mounted to the base radially outwardly fromthe center of the simulated drum and having a radially operable sensingmember seatable against the shoe lining for indicating the radialdistance from a simulated drum to the shoe liner;

wherein the meter may be calibrated to the standard drum radius, a brakeshoe positioned on the gage with its anchor eye seated against theanchor pin and its lining seated against the locator means, and

5 the meter sensing member can then indicate the clearance orinterference between the drum and the shoe lining.

5. A brake lining gage for supporting a brake shoe in a test plane formeasurement of clearances and interferences between a simulated standardbrake drum and the lining of the shoe, the gage comprising:

a. a base;

b. an anchor pin mounted to the base and extending through andperpendicular to the test plane for seating against the anchor eye ofthe brake shoe at a position simulating the anchor pin of a brakemechanism;

an outside diameter locator means mounted to the base, the locator meanshaving a locating surface extending through the test plane, for seatingagainst the lining at a position simulating and corresponding to astandard initial contact point for the shoe lining and the drum; and d.a distance indicating meter mounted to the base radially outwardly fromthe center of the simulated drum and having a radially operable sensingmember seatable against the shoe lining for indicating the radialdistance from a simulated drum to the shoe liner; wherein a series ofarcuately spaced radial slots are provided at a selected angularintervals on opposite sides of the outside diameter locator means forslidably mounting the meter to a selected slot wherein the meter may becalibrated to the standard drum radius, a brake shoe positioned on thegage with its anchor eye seated against the anchor pin and its liningseated against the locator means, and

the meter sensing member can then indicate the clearance or interferencebetween the drum and the shoe lining.

6. A gage according to claim 5, wherein a. a radially aligned series ofanchor bores are provided in the base for selectively positioning theanchor pin;

b. a series of outside diameter locator bores are provided in the baseand aligned along a radius perpendicular to the radius of alignment ofthe anchor bores, for selectively positioning the locator means; and

c. a center post is matingly mounted in a center bore in the base andspaced from the anchor pin at a distance simulating the center of astandard brake mechanism. I

7. A gage according to claim 6, wherein a. the meter is movably mountedto the base for radial adjustment;

. b. the outside diameter locating means is movably mounted to the basefor radial adjustment;

c. a drum radius setting bar is provided for seating at one end againstthe center post in radial alignment, the drum setting bar having anopposite end surface spaced a standard drum radius from the center ofthe center post, for seating at its opposite end against the outsidediameter locater means and the meter for calibrating them to thestandard drum radius;

d. the anchor pin is movably mounted to the base for radial adjustment;and

e. an anchor setting bar is provided for seating at one end against thecenter post in radial alignment and for seating at its opposite endagainst the anchor pin, the anchor bar having an effective lengthspacing the anchor pin a standard distance from the center of the centerpost.

8. A gage according to claim 7, wherein the base is mounted to a standfor aligning the test plane transverse to a horizontal work table withthe anchor pin relatively beneath the center post.

1. A brake lining gage for supporting a brake shoe in a test plane formeasurement of clearances and interferences between a simulated standardbrake drum and the lining of the shoe, the gage comprising: a. a base;b. an anchor pin mounted to the base and extending through andperpendicular to the test plane for seating against the anchor eye ofthe brake shoe at a position simulating the anchor pin of a brakemechanism; c. an outside diameter locater means movably mounted to thebase for radial adjustment the locator means having a locating surfaceextending through the test plane, for seating against the lining at aposition simulating and corresponding to a standard initial contactpoint for the shoe lining and the drum; d. a distance indicating metermounted to the base radially outwardly from the center of the simulateddrum and having a radially operable sensing member seatable against theshoe lining for indicating the radial distance from a simulated drum tothe shoe liner; e. a center post mounted to the base, extending throughand perpendicular to the test plane and spaced from the anchor pin at aposition simulating the center of the standard brake drum; and f. a drumradius setting bar for seating at one end against the center post and inradial alignment, and seating at its opposite end against the outsidediameter locator means, the drum radius setting bar having an oppositeend surface spaced a standard drum radius from the center of the centerpost, for calibrating the outside diameter locator means to the standarddrum radius; wherein the meter may be calibrated to the standard drumradius, a brake shoe positioned on the gage with its anchor eye seatedagainst the anchor pin and its lining seated against the locator means,and the meter sensing member can then indicate the clearance orinterference between the drum and the shoe lining.
 2. A brake lininggage for supporting a brake shoe in a test plane for measurement ofclearances and interferences between a simulated standard brake drum andthe lining of the shoe, the gage comprising: a. a base; b. an anchor pinmovably mounted to the base for radial adjustment and extending throughand perpendicular to the test plane for seating against the anchor eyeof the brake shoe at a position simulating the anchor pin of a brakemechanism; c. an outside diameter locator means mounted to the base, thelocator means having a locating surface extending through the testplane, for seating against the lining at a position simulating andcorresponding to a standard initial contact point for the shoe liningand the drum; d. a distance indicating meter mounted to the baseradially outwardly from the center of the simulated drum and having aradially operable sensing member seatable against the shoe lining forindicating the radial distance from a simulated drum to the shoe liner;e. a center post mounted to the base, extending through andperpendicular to the test plane and spaced from the anchor pin at aposition simulating the center of the standard brake drum; and f. ananchor setting bar for radial alignment and for seating at one endagainst the center post and for seating at its opposite end against theanchor pin, the anchor bar having an effective length for spacing theanchor pin a standard distance from the center of the center postwherein the meter may be calibrated to the standard drum radius, a brakeshoe positioned on the gage with its anchor eye seated against theanchor pin and its lining seated against the locator means, and themeter sensing member can then indicate the clearance or interferencebetween the drum and the shoe lining.
 3. A brake lining gage forsupporting a brake shoe in a test plane for measurement of clearancesand interferences between a simulated standard brake drum and the liningof the shoe, the gage comprising: a. a base; b. an anchor pin movablymounted to the base for radial adjustment and extending through andperpendicular to the test plane for seating against the anchor eye ofthe brake shoe at a position simulating the anchor pin of a brakemechanism; c. an anchor setting bar for seating at one end against thecenter post and for seating at its opposite end against the anchor pinin radial alignment, the anchor bar having an effective length spacingthe anchor pin a standard distance from the center of the center post;d. an outside diameter locator means movably mounted to the base forradial adjustment the locator means having a locating surface extendingthrough the test plane, for seating against the lining at a positionsimulating and corresponding to a standard initial contact point for theshoe lining and the drum; e. a distance indicating meter movably mountedto the base for radial adjustment radially outwardly from the center ofthe simulated drum and having a radially operable sensing memberseatable against the shoe lining for indicating the radial distance froma simulated drum to the shoe liner; f. a drum radius setting bar forseating at one end against the center post in radial alignment, the drumradius setting bar having an opposite end surface spaced a standard drumradius from the center of the center post, for seating against thesensing member of the meter for calibrating the meter to the standarddrum radius and the drum radius setting bar is also provided for seatingat one end against the center post in radial alignment, and seating atits opposite end against the outside diameter locator means forcalibrating the outside diameter locator means to the standard drumradius; and g. a center post mounted to the base, extending through andperpendicular to the test plane and spaced from the anchor pin at aposition simulating the center of the standard brake drum; wherein themeter may be calibrated to the standard drum radius, a brake shoepositioned on the gage with its anchor eye seated against the anchor pinand its lining seated against the locator means, and the meter sensingmember can then indicate the clearance or interference between the drumand the shoe lining.
 4. A brake lining gage for supporting a brake shoein a test plane for measurement of clearances and interferences betweena simulated standard brake drum and the lining of the shoe, the gagecomprising: a. a base having a radially aligned series of anchor boresfor selectively positioning an anchor pin and series of outside diameterlocator bores aligned along a radius perpendicular to the radius ofalignment the anchor bores for selectively positioning a locator meansb. an anchor pin mounted to the base and extending through andperpendicular to the test plane for seating against the anchor eye ofthe brake shoe at a position simulating the anchor pin of a brakemechanism; c. an outside diameter locator means mounted to the base, thelocator means having a locating surface extending through the testplane, for seating against the lining at a position simulating andcorresponding to a standard initial contact point for the shoe liningand the drum; and d. a distance indicating meter mounted to the baseradially outwardly from the center of the simulated drum and having aradially operable sensing member seatable against the shoe lining forindicating the radial distance from a simulated drum to the shoe liner;wherein the meter may be calibrated to the standard drum radius, a brakeshoe positioned on the gage with its anchor eye seated against theanchor pin and its lining seated against the locator means, and themeter sensing member can then indicate the clearance or interferencebetween the drum and the shoe lining.
 5. A brake lining gage forsupporting a brake shoe in a test plane for measurement of clearancesand interferences between a simulated standard brake drum and the liningof the shoe, the gage comprising: a. a base; b. an anchor pin mounted tothe base and extending through and perpendicular to the test plane forseating against the anchor eye of the brake shoe at a positionsimulating the anchor pin of a brake mechanism; c. an outside diameterlocator means mounted to the base, the locator means having a locatingsurface extending through the test plane, for seating against the liningat a position simulating and corresponding to a standard initial contactpoint for the shoe lining and the drum; and d. a distance indicatingmeter mounted to the base radially outwardly from the center of thesimulated drum and having a radially operable sensing member seatableagainst the shoe lining for indicating the radial distance from asimulated drum to the shoe liner; wherein a series of arcuately spacedradial slots are provided at a selected angular intervals on oppositesides of the outside diameter locator means for slidably mounting themeter to a selected slot wherein the meter may be calibrated to thestandard drum radius, a brake shoe positioned on the gage with itsanchor eye seated against the anchor pin and its lining seated againstthe locator means, and the meter sensing member can then indicate theclearance or interference between the drum and the shoe lining.
 6. Agage according to claim 5, wherein a. a radially aligned series ofanchor bores are provided in the base for selectively positioning theanchor pin; b. a series of outside diameter locator bores are providedin the base and aligned along a radius perpendicular to the radius ofalignment of the anchor bores, for selectively positioning the locatormeans; and c. a center post is matingly mounted in a center bore in thebase and spaced from the anchor pin at a distance simulating the centerof a standard brake mechanism.
 7. A gage according to claim 6, whereina. the meter is movably mounted to the base for radial adjustment; b.the outside diameter locating means is movably mounted to the base forradial adjustment; c. a drum radius setting bar is provided for seatingat one end against the center post in radial alignment, the drum settingbar having an opposite end surface spaced a standard drum radius fromthe center of the center post, for seating at its opposite end againstthe outside diameter locater means and the meter for calibrating them tothe standard drum radius; d. the anchor pin is movably mounted to thebase for radial adjustment; and e. an anchor setting bar is provided forseating at one end against the center post in radial alignment and forseating at its opposite end against the anchor pin, the anchor barhaving an effective length spacing the anchor pin a standard distancefrom the center of the center post.
 8. A gage according to claim 7,wherein the base is mounted to a stand for aligning the test planetransverse to a horizontal work table with the anchor pin relativelybeneath the center post.